891e6a9312
Commit a3d384029a aka
"[AX.25]: Fix unchecked rose_add_loopback_neigh uses"
transformed rose_loopback_neigh var into statically allocated one.
However, on unload it will be kfree's which can't work.
Steps to reproduce:
modprobe rose
rmmod rose
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000008
printing eip:
c014c664
*pde = 00000000
Oops: 0000 [#1]
PREEMPT DEBUG_PAGEALLOC
Modules linked in: rose ax25 fan ufs loop usbhid rtc snd_intel8x0 snd_ac97_codec ehci_hcd ac97_bus uhci_hcd thermal usbcore button processor evdev sr_mod cdrom
CPU: 0
EIP: 0060:[<c014c664>] Not tainted VLI
EFLAGS: 00210086 (2.6.23-rc9 #3)
EIP is at kfree+0x48/0xa1
eax: 00000556 ebx: c1734aa0 ecx: f6a5e000 edx: f7082000
esi: 00000000 edi: f9a55d20 ebp: 00200287 esp: f6a5ef28
ds: 007b es: 007b fs: 0000 gs: 0033 ss: 0068
Process rmmod (pid: 1823, ti=f6a5e000 task=f7082000 task.ti=f6a5e000)
Stack: f9a55d20 f9a5200c 00000000 00000000 00000000 f6a5e000 f9a5200c f9a55a00
00000000 bf818cf0 f9a51f3f f9a55a00 00000000 c0132c60 65736f72 00000000
f69f9630 f69f9528 c014244a f6a4e900 00200246 f7082000 c01025e6 00000000
Call Trace:
[<f9a5200c>] rose_rt_free+0x1d/0x49 [rose]
[<f9a5200c>] rose_rt_free+0x1d/0x49 [rose]
[<f9a51f3f>] rose_exit+0x4c/0xd5 [rose]
[<c0132c60>] sys_delete_module+0x15e/0x186
[<c014244a>] remove_vma+0x40/0x45
[<c01025e6>] sysenter_past_esp+0x8f/0x99
[<c012bacf>] trace_hardirqs_on+0x118/0x13b
[<c01025b6>] sysenter_past_esp+0x5f/0x99
=======================
Code: 05 03 1d 80 db 5b c0 8b 03 25 00 40 02 00 3d 00 40 02 00 75 03 8b 5b 0c 8b 73 10 8b 44 24 18 89 44 24 04 9c 5d fa e8 77 df fd ff <8b> 56 08 89 f8 e8 84 f4 fd ff e8 bd 32 06 00 3b 5c 86 60 75 0f
EIP: [<c014c664>] kfree+0x48/0xa1 SS:ESP 0068:f6a5ef28
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
112 lines
2.4 KiB
C
112 lines
2.4 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
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*/
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/timer.h>
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#include <net/ax25.h>
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#include <linux/skbuff.h>
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#include <net/rose.h>
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#include <linux/init.h>
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static struct sk_buff_head loopback_queue;
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static struct timer_list loopback_timer;
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static void rose_set_loopback_timer(void);
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void rose_loopback_init(void)
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{
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skb_queue_head_init(&loopback_queue);
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init_timer(&loopback_timer);
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}
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static int rose_loopback_running(void)
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{
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return timer_pending(&loopback_timer);
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}
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int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh)
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{
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struct sk_buff *skbn;
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skbn = skb_clone(skb, GFP_ATOMIC);
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kfree_skb(skb);
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if (skbn != NULL) {
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skb_queue_tail(&loopback_queue, skbn);
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if (!rose_loopback_running())
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rose_set_loopback_timer();
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}
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return 1;
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}
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static void rose_loopback_timer(unsigned long);
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static void rose_set_loopback_timer(void)
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{
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del_timer(&loopback_timer);
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loopback_timer.data = 0;
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loopback_timer.function = &rose_loopback_timer;
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loopback_timer.expires = jiffies + 10;
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add_timer(&loopback_timer);
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}
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static void rose_loopback_timer(unsigned long param)
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{
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struct sk_buff *skb;
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struct net_device *dev;
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rose_address *dest;
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struct sock *sk;
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unsigned short frametype;
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unsigned int lci_i, lci_o;
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while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
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lci_i = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
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frametype = skb->data[2];
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dest = (rose_address *)(skb->data + 4);
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lci_o = 0xFFF - lci_i;
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skb_reset_transport_header(skb);
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sk = rose_find_socket(lci_o, rose_loopback_neigh);
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if (sk) {
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if (rose_process_rx_frame(sk, skb) == 0)
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kfree_skb(skb);
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continue;
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}
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if (frametype == ROSE_CALL_REQUEST) {
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if ((dev = rose_dev_get(dest)) != NULL) {
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if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0)
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kfree_skb(skb);
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} else {
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kfree_skb(skb);
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}
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} else {
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kfree_skb(skb);
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}
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}
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}
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void __exit rose_loopback_clear(void)
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{
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struct sk_buff *skb;
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del_timer(&loopback_timer);
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while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
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skb->sk = NULL;
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kfree_skb(skb);
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}
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}
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